Before World War I, the Levant was part of the Ottoman Empire and was organized mainly through provinces and districts rather than modern international borders. Movement, taxation, and policing followed administrative lines that could shift over time. This mattered because later European border-making often tried to convert these older, flexible divisions into fixed state frontiers.
During the war, Britain and France negotiated the Sykes–Picot Agreement, which sketched zones of influence in the Arab provinces of the Ottoman Empire. Although not a final border treaty, it set expectations that the postwar settlement would split authority between the two powers. These assumptions later fed directly into boundary-making under the mandate system.
At the San Remo Conference, the Allied powers allocated former Ottoman territories as League of Nations mandates, setting France on a path to control Syria and Lebanon and Britain to control Palestine and Mesopotamia. This decision created the political need for clear, mapped boundaries between the new mandate areas. It also turned earlier wartime understandings into a governance problem that required technical demarcation.
Britain and France signed a convention in Paris covering practical issues between their future mandate territories, including a mechanism for experts/commissions to handle cross-border questions. While the convention did not fully settle every line on the ground, it established a formal framework to translate broad political agreements into workable frontiers. This became the legal-administrative bridge from diplomacy to field surveying.
A Franco-British boundary commission, associated with French Lt. Col. N. Paulet and British Lt. Col. S. F. Newcombe, began fieldwork to mark the frontier between French-mandate Syria/Lebanon and British-mandate Palestine. The work involved turning political claims into mapped lines and physical points that officials could administer. This step mattered because it converted a negotiated idea of a border into a surveyed boundary intended to be enforceable.
As the commission worked through 1921, it selected specific turning points along the frontier and prepared detailed maps to support the line. The aim was to minimize administrative confusion and to make customs, policing, and local governance possible in practice. Choices about terrain, roads, and water access meant the technical work also had long-term political effects.
The boundary commission signed its final report on fixing the borders between Lebanon and Syria on one side and Palestine on the other. This report represented the commission’s agreed technical solution after field investigation, including adjustments from earlier, broader political understandings. It became the key technical reference used for subsequent governmental approval.
The demarcation work produced a system of numbered points (often described as 71 primary points, including 38 along the Lebanon–Palestine sector) intended to anchor the border on the ground. These markers were meant to reduce disputes by giving administrators fixed references rather than relying only on text descriptions. Over time, damage or loss of markers would contribute to later difficulties in locating the precise line.
Britain and France signed the treaty “respecting the Boundary Line between Syria and Palestine from the Mediterranean to El Hammé” in Paris. This agreement is widely known as the Paulet–Newcombe Agreement/Line, after the two officers associated with the commission’s work. It mattered because it turned the commission’s technical outcome into a formal interstate agreement between the two mandatory powers.
After the treaty was signed, the mandate authorities exchanged memoranda and treated the demarcation as effective shortly afterward. This step was important because it linked the paper agreement to administrative action—how officials actually ran border crossings, enforced rules, and managed land and security issues along the new line. In practice, this is when the boundary began functioning as an operational frontier.
During the mandate period, the line demarcated by the commission was treated as the international border for administration and later referenced in subsequent agreements. This continuity mattered because it embedded the commission’s technical decisions—points, pillars, and mapped segments—into later legal and diplomatic practice. It also meant later disputes often focused on interpreting or relocating the original markers rather than renegotiating the whole concept of the border.
The boundary agreement was registered with the League of Nations, strengthening its international standing in the mandate system. Registration mattered because it placed the border settlement into a recognized international record, supporting later claims that the frontier had legal status beyond local administrative practice. This step helps explain why the 1920–1923 demarcation remains a key reference point in later border discussions.
Franco‑British Boundary Commission and the Syria–Lebanon border demarcation (1920–1923)